Radioreceiving system



E. W. KELLOGG.

RADIORECEIVING SYSTEM. APPLICATION FILED APR. 21. 1921.

. Patented NOV. 7, 1922. f 6 Fig. 1.

, InVentor: Edward W. Kellogg, by flaw 4. M

Hi5 #Ittorney Patented Nov. 7, 1922.

UNITED STATES 1,434,707 PATENT OFFICE.

EDWARD KELLOGG, OF SCHEN ECTADY, NEW YORK, ASSIGNOR TO GENERAL ELEC- TRIC COMPANY, A CORPORATION OF NEW YORK.

RADIORECEIVING SYSTEM.

Application filed April 21,

To all whom it may concern:

Be it known that I, EDWARD WV. KELLOGG, a. citizen of the United. States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful" Improvements in Radioreceiving Systems, of which the following is a specification.

My present invention relates to radio re ceiving systems, and more particularly to systems of theclass in which a plurality of widely separated receiving antennae are con nected by transmission lines to a. central receiving station.

One of the objectsof my invention is to provide an improved method of operating such a system whereby an efficient reception of desired signals may be secured and the effects of disturbing influences either from nearby stations or from static may be minimized. Another object of my invention is to provide an improved system-of the class described whereby a more efficient reception of desired signals may be obtained.

In order to attain the objects of my inventionsl provide a plurality of receivlng antennae which are located at widely separated points, so chosen geographically that the intensity or phase relation betweenthe signaling'impulses and disturbing influences Wlll be different at the different points of reception. I also provide means for selectively impressing the currents received upon the receiving apparatus so that it will be possible'tto select for the desired reception the currents having the most favorable ratio between s-ignal and disturbin influence. In addition I provide means for varying the phase and intensity of the currents impressed upon the receiving apparatus so that by suitable adjustment the signaling currents received upon different antennae may be brought into phase or approximate; phase with one another and caused to add amplitudes in the receiving apparatus while the disturbing influences will at the same time be more or less out of phase and will cornbine in heterogeneous phase relation and therefore increase less rapidly than the desired signal with an increasing number of receiving antennae. As a result the stray ratio will be greatly improved.

When the receiving antennae are' widely,

sired signaling currents and disturbing insepara-ted long transmision lines must be employed for transmitting the received sig- 1921. Serial No. 463,264.

naling currents to the receiving station. This involves Cllfl'lCllltlES in line constructlon to reduce the line losses to a minimum ifthe received signals are transmitted at radio frequency. To overcome this disadvantage I provide detectors at each of the receiving antennae and transmit the detected currents over the transmission lines to the central receiving station. As a result, the line construction may be greatly simplified and the line losses greatly reduced. In case contin uous wave signals are to be received it is desirable that the detected currents shall all be of the same frequency, and that a constant relative phase relation shall be maintained. To secure this result, I provide a single source of current at the receiving station for controlling the operation of all of the detectors and utilize the transmission lines for transmitting this curent to the individual detectors. In order to eliminate the necessity of transmitting any high frequency current over the transmission lines, this source maybe of comparatively low frequency, and by providing frequency multipliers at each receiving antennae the frequency of the current transmitted may be multiplied to produce the high frequency current desired for theoperation of the detectors.

The novel features which I believe to be characteristic of my invention are set forth with particularity'in the appended claims; my invention itself, however, both as to its organization and method of operation will best be understood by reference to the following description taken in connection with the accompanying drawing in which Fig. 1 shows diagrammatically a simple form of receiving system whereby my invention may be carried into effect, and Fig. 2 illustrates a modification of the manner of transmitting the'control currents from the receiving station to the individual detectors.

As indicated in Fig. 1, my receiving station comprises a plurality of widely separated receiving antennae 1, 2, 3, 4, 5, connected by individual transmission lines 6, 7,

"8, 9 and 10, to a central receiving station.

fluences, either of static or interfering stations will normally be different at the differ ent antennae.

TVhile all of the receiving antennae may be located at a distance from the receiving station, it is obvious that if desired one of them, for example, antennae 2, may be located at the receiving station. The currents received upon the separate antennae are impressed by means of the usual coupling transformers upon individual detectors 11, 12, 13, 14, 15. In order that the currents of lower than signaling frequency produced by means of all of these detectors shall have the same frequency, I provide a single source of control current 16 at the receiving station. The current supplied by this source should preferably be of a frequency materially different from the frequency of the current to be produced in the detectors, but of a. frequency low enough to be transmitted without undue losses or restoring to special line construction. This will in general be materially below the frequency of the signaling currents to be received. The frequency of the source 16 may be higher or lower than that of the detected currents tobe transmitted, and in the present case I have inclicated it as of higher frequency. The control current from the source 16 may be impressed upon the transmission lines through condensers 17 at the receiving station and from the transmission lines upon frequency multipliers 18, 19, 20, 21 and 22 through condensers 23 at the separate receiving points. These condensers should be of such value as to offer a high impedance tothe low frequency signaling currents produced by the detectors whereby the efiiciency of transmission of these low frequency currents will be unimpaired. Choke coils 24: at the receiving station and 25 at the individual receiving points may be provided to keep the higher frequency control current fro-1n circulating in portions of the system where they are not desired. a

The frequency of the source 16 is so chosen that in conjunction with the fre quency multipliers a. current of desired frequency may be obtained for the operation of detectors in order to produce therein currents which will preferably be of audio frequency for transmission to the central receiving station. The currents thus produced and transmitted over the transmission lines to the receiving station may be im-- pressed by means of intensity couplers 26 and phase rotators 27 upon the receiving apparatus which may be of any type desired. I have indicated it in the present case merely by a rectangle 28.

Any convenient means, such, for example, as switches 29. 30, 31, 32 and 33 may be employed for selectively impressing upon the receiving apparatus signaling currents received upon any one or more of the antennae. By varying the adjustment of the phase rotators and intensity couplers the desired signaling currents received upon any two or more of the antennae may be brought into phase or approximate phase with one another so as to add amplitudes in the receiving apparatus, while the currents due to disturbing influences which are in some cases local, and in other cases general but come from miscellaneous directions will combine in heterogeneous phase relations, and will merely oppose energies.

The apparatus indicated may be utilized for receiving in a large variety of ways. It may be found that currents received upon one of the antennae have a much more favorable stray ratio than the currents received upon any of the other antennae, in which case the current having the most favorable stray ratio may be selected for the desired reception, and this current alone impressed upon the receiving apparatus.

By selectively combining the currents from two or more different antennae in different ways and with varying phase and intensity adjustments, a combination may be obtained which gives the most favorable stray ratio and this particular combination may then be utilized for the desired reception. By means of the apparatus indicated the individual antenna or combination of antennae employed for reception may be varied at will to meet varying disturbing conditions, such for example as disturbances produced by thunderstorms travelling across the country in such a way that at one time one of the receiving antennas is most seriously affected while a little later one of the other antennae is affected. to. a greater extent.

In Fig. 2 I have shown a modification of my invention which may be employed where the current for controlling the operation of the detecto's is too near the frequency of the signaling current to be transmitted from the detectors to the receiving station to be conveniently separated therefrom by the arrangement of detectors and choke coils indicated in Fig. 1. A balanced circuit is pro vided in this case by means of artificial lines 3-1 and 35 or circuits having approximately the same impedance as the transmission line so that current from the source 16 will produce no effect in the intensity coupler 26 and the beat current produced by the detector 11 will not be supplied to the frequency multiplier 18.

Vhile I have indicated and described the preferred embodiments of my invention, it will be apparent that my invention is by no means limited to the particular embodiments shown and described, but that many modifications in the arrangement and connections and method of operating the apparatus may be made without departing from the scope claims.

of my inventi'onas set forth in the appended Vi hat I claim as new and desire to secure sists in transmitting over thetransmission lines from the central receivingstation currents of a frequency, materially, lower than that of the signaling waves to-be received, multiplying the frequency ,of the currents thus transmitted at each receiving antenna' to produce a current of a frequency slightly different from thatof the signaling Waves to be received, utilizing the currents thus produced for the operation of the detectors and thereby producing audio frequency currents and transmittingthe audio frequency currents thus produced to the re ceiving station 2. The method of operating a radio'receivlng system compris1nga plurality of widely separated receiving antennae and local detectors connected by transmission lines to a central receiving station which consists in transmitting over the transmission lines from the central receiving station cur rents 'of'a frequency materlally lower than that of the signaling waves to be received, multiplying the-frequency of the currents thus transmitted at each" receiving antenna to produce a current ofafrequency f slightly different from that of the signaling waves to be. received, utililzing'the currents thus produced for the operation of the detectors and thereby producing audio frequency currents of ,a frequency materially lower than that of the currents transmitted from the receivingstation, and transmitting the audio frequency currents thus produced to the receiving station.

3. The method'of operating a radio receiving system comprising a plurality of widely separated receiving antennaeand local detectors connected by transmission lines to a central receiving station which consists in transmitting over the transmission lines from the central receiving station currents of a frequency materially lower than that of the signaling waves to be received, multiplying the frequency of the currents thus transmitted at each receiving antenna utilizing the currents thus produced for the operation of the detectors and thereby producing audio frequency currents and transmitting the audio frequency currents thus produced to the receiving station.

l. The method of operating a radio receiving system comprising a plurality of widely separated receiving antennae and local detectors connected by transmission lines to a central receiving station which consists in transmitting over the transmission lines from the central receiving station currents of a frequency materially lower than that of the signaling Waves to be received, multiplying the frequency of the currents thus transmitted at each receiving antenna, utilizing the currents thus produced for the operation of the detectors and thereby producing audio "frequency currents of a frequency materially lower than that of the currents transmitted from the receiving station, and transmitting the audio frequency currents thus produced to the receiving station.

5 The method of operatinga radio receiving system comprising a plurality of widely separated receiving antennae and local detectors connected by transmission lines to a central receiving station which consists in transmitting over the transmission lines from the central receiving station currents of a frequency materially lower than that of the signaling waves'to be received, multiplying the frequency of the currents thus transmitted at each receiving antenna, utilizing the currents thus produced for the operation of the detectors and thereby producing currents of a frequency materially different from that of the currents transmitted from the receiving station and transmitting the currents of different frequency thus produced to the receiving station.

6. The combination in a radio receiving system of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving antennae with the receiving station, a detector associated with each of said antennae, a-source of control current at the receiving station of materially lower fre quency than that of the signaling waves to be received, means for impressing the con"- trol current upon the transmission lines,

means at each antenna for multiplying the frequency of the current transmitted over the transmission lines, means for impressing the current of multiplied frequency upon the detectors to produce audio frequency cur rents therein and means for impressing the audio frequency currents thus produced upon the transmission lines.

7. The combination in a radio receiving system of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving antennae with the receiving station, a detector associated with each of said antennae, a source of control current at the receiving station of materially lower frequency than that of the signaling waves to be received, means for impressing the control current upon the transmission 1ines,means at each antenna for multiplying the frequency of the current transmitted over the transmission lines, means for impressing the current of multiplied frequcncy'upon the detectors to produce audio frequency currents therein, of a frequency materially lower than that of the currents transmitted from the receiving station; and means for impressing the audio frequency currents thus produced upon the transmission lines. o

8. The combination in a radio receiving system of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving antennae-with the receiving station, a detector associated with each of said antennae, a source of control current at the receiving station of materially lower frequency than that of the signaling waves to be received, means for impressing the control current upon the transmission lines, means at each antennae for multiplying the frequency of the current transmitted over the transmission lines to produce a current of a frequency slightly dif' ferent from that of thesignaling waves to be received, means for impressing the current of multiplied frequency upon the detectors to produceaudio frequency currents therein, and means for impressing the audio frequency currents thus produced upon the transmission lines.

9. The combination in a radio receiving system of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving antennze with the receiving station, a detector associated with each of said antennae, a source of control current at the receiving station of materially lower frequency than that of the signaling waves to he received, means for impressing the control current upon the transmission lines means for each antenna for multiplying the frequency of the current transmitted over the transmission lines, means for impressing the current of multiplied frequency upon the detectors to produce currents therein, of afrequency materially lower than that of the currents transmitted from the receiving station, and means for impressing the currents thus produced upon the transmission lines.

The combination in a radio receiving system of a plurality of widely separated receiving antennae, receiving apparatus located at a central receiving station, transmission lines connecting each of said receiving antennae with the receiving station, a detector associated with each of said antennae, a source of control current at the receiving station of materially lower frequency than that of the signaling waves to be received, means for impressing the control current upon the transmission lines, means at each antenna for multiplying the frequency of the currents transmitted over the transmission lines, means for impressing the current of multiplied frequency upon the detectors to produce currents therein of a frequency different from that of the currents transmitted from the receiving station, and means for impressing the currents thus produced upon the transmission lines.

In witness whereof I have hereunto set my hand this th day of April 1921.

EDWARD W. KELLOGG. 

